Rat Sciatic Nerve Regeneration Using a Collagen Bioimplant

A collagen mafrix (COL)gel was .used to fill a 3 mm gap resulting from transection of rat sdatic nerve. The nerve was initially stabilized with a split polyethylene tubing in order to remove elastic tension at the nerve repair site. The contralateral sdatic nerve was identically prepared but the gap was left empty. Animal survival time was '9 to 12 weeks. One day prior to killing. somatosensory evoked potentials and injections of the tracer. horseradish peroxidase on distal potentials and injections of the tracer, horseradish peroxidase on distal nerves were done. Morphological analysis of the nerve preparations included light microscopy. silver staining for axons and histochemical fluorescence of catecholamines. Horseradish peroxidase granules were observed proximal to the regenerate in both COL and controls. Light and electron misroscopic results indicate that COL-treated animals had significantly improved axonal outgrowth across and distal to the bridge matrix compared to the untreated group. The microscopic findings were supported by the somatosensory evoked potentials activity recorded from COL treated animals at the end of the observation period.